"More Catholic than the Pope", "more royalist than the King": this phrase in Hungarian uses a suffix reserved for adjectives because there has been a "conversion" of a noun into an adjective.
Some nouns can be turned into adjectives and keep only their negative meaning: szemét, mocsok, etc., or more rarely positive: király, etc., then these too can get suffixes reserved for adjectives: szemetebb, királyabb, királyul. But this is a distortion of meaning proper to the unacademic spoken language.
-- Olivier

Olivier, I agree, except for the "distortion"-bit.
It is a totally normal (even "stilisztikailag különösen hatásos" according to Nyelművelő Kézikönyv) usage to apply the -bb to a noun used as an adjective if
a) it is used to qualify (in either positive or negative way*) somebody or something e.g. like frank's example above or "emberibb", "kutyább" etc.
b) if the noun indicates direction, like e.g. keletebb(re), nyugatabb(ról) etc.

It is interesting to note that some nouns can take the suprlative's "leg"(/legesleg) when indicating a relation to the position of their other parts e.g. (a fa) legcsúcsa, legeslegtetején (leg/legesleg+noun+poss.suffix+...) without being able to take the form with "-bb" (= középfok jele).

*the positive meaning is mainly used in an elevated register, the negative especially in spoken language

Olivier's examples are more common than my "pápább". The "király" is widely used as adjective in the youth's informal language in the sense of "super", "very good. The "pápább" is used only in the cited saying - as far as I know. "Szemét" and "mocsok" are used as adjectives in free context, too.

... The "király" is widely used as adjective in the youth's informal language in the sense of "super", "very good. The "pápább" is used only in the cited saying - as far as I know...

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Yes, but even "király" in that sense is a fairly new usage that may fade when a new/another fashion (expression) comes.
As popes don't have as much influence in people's everyday life anymore, maybe this is why there are no other expressions with the word.